Gradient structured metals have been reported to exhibit high strength and high ductility.
Here we report that the strength of gradient structured aluminum rod is much higher than the
value calculated using the rule of mixtures. The mechanical incompatibility in the gradient
structured round sample produced 3D stress states, extraordinary strengthening and good
ductility. An out of plane {111} wire texture was developed during the testing, which
contributes to the evolution of the stress state and mechanical behavior.